Reverse flow heat exchanger for exhaust systems

Abstract

An exhaust system includes a reverse flow heat exchanger having a plate separating an intake chamber and an exit chamber, each chamber having an inlet and an outlet located at opposing ends to allow flow therethrough. The plate can include a vane connected to the end of the plate in the vicinity of an inlet or an outlet. The vane is configured to reduce resistance to fluid flow near the intake chamber inlet. The exhaust system includes a heating manifold, such as a combustion chamber, configured to receive an exhaust stream from the intake chamber, further heat the exhaust stream, and return the exhaust stream to the exit chamber. Embodiments of the system can be configured to additionally perform as a catalytic converter and/or a muffler.

1 . An exhaust system comprising:
 a first exhaust manifold configured to receive exhaust gas;   a reverse flow heat exchanger coupled to the first exhaust manifold, the reverse flow heat exchanger including:
 an intake chamber having an intake chamber inlet and an intake chamber outlet to allow flow therethrough, the intake chamber inlet configured to receive exhaust gas from the first exhaust manifold, 
 an exit chamber having an exit chamber inlet and an exit chamber outlet to allow flow therethrough, the exit chamber inlet configured to receive heated exhaust gas from the intake chamber; and 
   a heating manifold configured to receive exhaust gas from the intake chamber, heat the received exhaust gas, and provide the heated exhaust gas to the exit chamber inlet.   
   
   
       2 . The exhaust system of  claim 1  wherein the intake chamber inlet and the intake chamber outlet are located at opposing ends. 
   
   
       3 . The exhaust system of  claim 1  wherein the exit chamber is configured to transfer heat to the intake chamber. 
   
   
       4 . The exhaust system of  claim 1  wherein the reverse flow heat exchanger further includes a plate separating the intake chamber and the exit chamber, the plate configured to transfer heat from the heated exhaust gas in the exit chamber to the exhaust gas in the intake chamber. 
   
   
       5 . The exhaust system of  claim 1  further comprising a flow element within the first exhaust manifold, the flow element disposed relative to the intake chamber inlet so as to reduce resistance to fluid flow near the intake chamber inlet. 
   
   
       6 . The exhaust system of  claim 5  wherein the flow element extends from the intake chamber into the first exhaust manifold. 
   
   
       7 . The exhaust system of  claim 5  wherein the flow element includes a rounded end. 
   
   
       8 . The exhaust system of  claim 1  further comprising a flow element within the first exhaust manifold, the flow element configured to increase an effective orifice size of the intake chamber inlet. 
   
   
       9 . The exhaust system of  claim 1  further comprising a second exhaust manifold coupled to the reverse flow heat exchanger and configured to receive exhaust gas from the exit chamber outlet. 
   
   
       10 . The exhaust system of  claim 9  wherein the first and the second exhaust manifolds are connected and separated by a baffle. 
   
   
       11 . The exhaust system of  claim 1  further comprising an energy source configured to produce radiation within the heating manifold. 
   
   
       12 . The exhaust system of  claim 11  wherein the energy source increases a temperature to an ignition temperature of a particle in the received exhaust gas. 
   
   
       13 . The exhaust system of  claim 1  wherein the heating manifold uses heat from combustion of particles in the received exhaust gas to heat the exhaust gas. 
   
   
       14 . The exhaust system of  claim 1  wherein the reverse flow heat exchanger further includes a thermal insulation layer. 
   
   
       15 . A reverse flow heat exchanger configured to receive exhaust gas from an exhaust manifold, the reverse flow heat exchanger comprising:
 a set of intake chambers, each intake chamber having an inlet and an outlet, the inlets of the intake chambers configured to receive exhaust gas from the exhaust manifold;   a set of exit chambers, the exit chambers alternating with the intake chambers, each exit chamber having an inlet and an outlet, the inlets of the exit chambers configured to receive heated exhaust gas from the intake chambers; and   a plurality of heat transfer elements separating the exit chambers and the inlet chambers, the heat transfer elements configured to transfer heat from the exit chambers to the intake chambers and heat exhaust gas in the intake chambers.   
   
   
       16 . The exhaust system of  claim 15  further comprising a heating manifold coupled to the reverse flow heat exchanger and configured to receive exhaust gas from the intake chambers, heat the received exhaust gas, and provide the heated exhaust gas to the inlets of the exit chambers. 
   
   
       17 . The exhaust system of  claim 16  wherein energy from combustion of a particle in the exhaust gas is used to heat the exhaust gas in the heating manifold. 
   
   
       18 . The exhaust system of  claim 16  further comprising a resistive heating element configured to heat the received exhaust gas within the heating manifold. 
   
   
       19 . The exhaust system of  claim 18  wherein the resistive heating element increases a temperature of a particle in the received exhaust gas to an ignition temperature. 
   
   
       20 . The exhaust system of  claim 15  further comprising an exit manifold coupled to the reverse flow heat exchanger and configured to receive exhaust gas from the exit chamber outlet of the reverse flow heat exchanger. 
   
   
       21 . The exhaust system of  claim 15  wherein the heat transfer elements separating the exit chambers and the inlet chambers include parallel plates. 
   
   
       22 . An exhaust system for removing particles from exhaust gas, the exhaust system comprising:
 an exhaust manifold and   a reverse flow heat exchanger coupled to the exhaust manifold and including a plurality of plates separating a number of chambers, the chambers comprising a set of intake chambers alternating with a set of exit chambers, each intake chamber having an inlet and an outlet, each exit chamber having an inlet and an outlet, the inlets of the intake chambers configured to receive exhaust gas from the exhaust manifold and configured to receive exhaust gas from the exhaust manifold and the inlets of the exit configured to receive heated exhaust gas from the intake chambers, the intake chamber configured to receive heat from the exit chamber.   
   
   
       23 . The exhaust system of  claim 22  wherein at least two of the plurality of plates are parallel. 
   
   
       24 . The exhaust system of  claim 22  further comprising a combustion chamber coupled to the reverse flow heat exchanger, the combustion chamber configured to receive exhaust gas from the outlets of the intake chambers and to provide heated exhaust gas to the inlets of the exit chambers. 
   
   
       25 . The exhaust system of  claim 24  wherein the combustion chamber is configured to raise a temperature of the exhaust gas to facilitate combustion of particles in the exhaust gas. 
   
   
       26 . The exhaust system of  claim 24  wherein the combustion chamber includes a heating source configured to heat the received exhaust gas to an ignition temperature particles in the received exhaust gas. 
   
   
       27 . The exhaust system of  claim 22  further comprising a plurality of vanes extending from the plates into the exhaust manifold. 
   
   
       28 . The exhaust system of  claim 27  wherein the vanes are feathered. 
   
   
       29 . The exhaust system of  claim 22  wherein the reverse flow heat exchanger further includes a thermal insulation layer. 
   
   
       30 . The exhaust system of  claim 22  wherein the chambers are configured to act as resonating chambers. 
   
   
       31 . A method for removing particles from exhaust gas comprising:
 receiving emitted exhaust gas containing particles from an exhaust manifold;   heating the emitted exhaust gas to an ignition temperature of the particles to produce heated exhaust gas;   burning the particles in the heated exhaust gas;   flowing the heated exhaust gas in thermal contact with the emitted exhaust gas; and   transferring heat to the emitted exhaust gas from the heated exhaust gas.   
   
   
       32 . The method of  claim 31  wherein the transferred heat to the emitted exhaust gas includes residual heat of combustion of the particles burned in the heated exhaust gas. 
   
   
       33 . The method of  claim 31  wherein heating the emitted exhaust gas includes radiating the emitted exhaust gas.